<!DOCTYPE html>
<html>
<head>
	<title></title>
	<style type="text/css">
		.box{
			width: 600px;height: 500px;
			border:1px solid;margin:0 auto;
		}
		.nav{
			width: 100%;height: 50px;background-color: lightblue;
		}
		.info{
			width: 100%;height: 400px;
		}
		.info_left{
			width: 70%;height: 100%;
			background-color: yellow;
			/*左浮动*/
			float: left;
		}
		.info_right{
			width: 30%;
			height: 100%;
			background-color: green;
			/*右浮动*/
			float: right;
		}
		.footer{
			width: 100%;height: 50px;
			background-color: orange;
		}
	</style>
</head>
<body>
	<div class="box">
		<!-- 导航 -->
		<div class="nav"></div>
		<!-- 内容展示区 -->
		<div class="info">
			<div class="info_left"></div>
			<div class="info_right"></div>
		</div>
		<!-- 网页底部 -->
		<div class="footer"></div>
	</div>
</body>
</html>